Hydrocarbon-peroxy hydrocarbon phosphonates

ABSTRACT

(Hydrocarbon-peroxy hydrocarbon) phosphonates, useful as polymerization initiators, may be prepared by the reaction of a hydroperoxide with a phosphonate of an unsaturated hydrocarbon.

May 6, 1975 HYDROCARBON-PEROXY HYDROCARBON PHOSPHONATES [75] Inventors: Lothar G. Dulog, Latem; Willy P.

Broeckx, Reet, both of Belgium [73] Assignee: S.A. Texaco Belgium N.V., Brussels,

Belgium [22] Filed: Sept. 25, 1972 [21] Appl. No.: 291,868

[52] US. Cl 260/961; 260/88] R; 260/895 R; 260/928 R; 260/935 R; 260/551 P; 260/941; 260/950; 260/956; 260/958; 260/968 [5 1] Int. Cl C07f 9/40; C08f 3/74 [58] Field of Search 260/961, 610 R, 551 P [5 6] References Cited UNITED STATES PATENTS 3,267,066 8/[966 Tijssen l, 260/6l0 R FQREIGN PATENTS OR APPLICATIONS 658,522 l0/l95l United Kingdom 260/6l0 R Primary Examiner-Anton Hw Sutto Attorney, Agent, or FirmT. l-l. Whaley; C G. Ries; Carl G. Seutter ABSTRACT (Hydrocarbon-peroxy hydrocarbon) phosphonates, useful as polymerization initiators, may be prepared by the reaction of a hydroperoxide with a phosphonate of an unsaturated hydrocarbon.

4 Claims, No Drawings HYDROCARBON-PEROXY HYDROCARBON PHOSPHONATES This invention relates to a process for preparing (hydrocarbon-peroxy hydrocarbon) phosphonates and to the novel products so prepared. More specifically, this invention relates to novel (hydrocarbon-peroxy hydrocarbon) phosphonates and their use as polymerization initiators.

BACKGROUND OF THE INVENTION As is well known to those skilled in the art. a wide variety of phosphorus-containing compounds has heretofore been prepared by various processes. It has not however heretofore been possible to prepare (hydrocarbon peroxy hydrocarbon) phosphonates.

It is an object of this invention to provide a process for preparing product (hydrocarbon peroxy hydrocarbon) phosphonates. It is another object of this invention to provide novel products including (alkylperoxy hydrocarbon) phosphonates which may find a wide variety of uses. including use as polymerization initiator. Other objects will be apparent to those skilled in the art.

STATEMENT OF THE INVENTION In accordance with certain of its aspects. the novel process of this invention for preparing product (hydrocarbon peroxy hydrocarbon) phosphonates n x P R" oon may comprise reacting a phosphonate of an unsaturated hydrocarbon x P R'H (11) with a hydroperoxide ROOH wherein R is hydrocarbon. R' is a divalent ethylenically unsaturated moiety having an alphahydrogen atom. R" is divalent hydrocarbon. and X is -OR or NR thereby forming said product (hydrocarbon peroxy hydrocarbon) phosphonate; and recovering said product.

DESCRIPTION OF THE INVENTION The charge phosphonate of an unsaturated hydrocarbon. typically an alkenyl phosphonate. which may be employed in practice of this invention may be a compound having the formula:

X P R H wherein R is a divalent ethylenically unsaturated moiety having an alpha-hydrogen atom. The double bond of the R group is attached to the alpha-carbon i.e., the carbon atom attached to the phosphorous atom. It will be apparent that R'H may thus be an alkenyl group, and preferably an alpha-alkenyl or l-alkenyl group. The R'H group may be a hydrocarbon group containing adjoining ethylenically unsaturated carbon atoms. i.e., carbon atoms having an ethylenically active double bond therebetween. Typical of the -R'H groups may be alkenyl groups including aralkenyl. and such groups when inertly substituted. When R'H is alkenyl it may typically be vinyl or 2-substituted vinyl such as l-propenyl. l-butenyl. l-pentenyl. etc. When RH is aralkenyl. it may typically be 2-phenylethenyl. 3-phenyl-l-propenyl. 4-tolyll-butenyl. etc. R'H may be inertly substituted i.e., it may bear a non-reactive substituent such as alkyl. aryl. cycloalkyl. ether. halogen, etc. Typically inertly substituted R'H groups may include 3-chloropropenyl, 2- ethoxyethenyl. carboethoxyethenyl, pchlorophenethenyl, etc. The preferred R' H groups may be lower alkenyl, i.e.. C -C alkenyl groups including eg vinyl. l-propenyl, l-butenyl. etc.

It will be apparent to those skilled in the art that when a given formula or equation includes more than one group designated by the same symbol (eg. R. R. R", X. etc.), they need not be the same. Thus in formula lI. supra one X might be ethoxy and one X might be methoxy.

The preferred R'H groups may be the alken-l -yl i.e.. alkenyl groups wherein the double bond is present on the alpha or first carbon. Typical of these groups may be vinyl. which is preferred. When R'H is vinyl. the compound may be a vinyl phosphonate. It will be clear from inspection that the R unsaturated group of the charge compound may be converted to the divalent R" group in the product.

In the charge phosphonate. the X group may be OR or NR R may be a hydrocarbon radical selected from the group consisting of alkyl. aralkyl. cycloalkyl. aryl. alkaryl. alkenyl. and alkynyl (with the unsaturated bonds not alpha to oxygen or nitrogen) including such radicals when inertly substituted. When R is alkyl. it may typically be methyl. ethyl. n-propyl. isopropyl. n-butyl. i-butyl. sec-butyl. amyl. octyl. decyl. octadecyl, etc. When R is aralkyl. it may typically be benzyl. beta-phenyl-ethyl. etc. When R is cycloalkyl. it may typically be cyclohexyl. cycloheptyl. cyclooctyl. Z-methylcycloheptyl. 3-butylcyclohexyl. 3- methylcyclohexyl. etc. When R is aryl. it may typically be phenyl. naphthyl. etc. When R is alkaryl. it may typically be tolyl. xylyl. etc. When R is alkenyl (with the unsaturated bond not alpha to oxygen or nitrogen) it may typically be l-propenyl. l-butenyl. etc. When R is alkynyl (with the triple bond not alpha to oxygen or nitrogen), it may typically be l-propynyl, l-butynyl. etc. R may be inertly substituted i.e.. it may bear a nonreactive substituent such as alkyl, aryl. cycloalkyl. ether, halogen. nitro. etc. Typically inertly substituted R groups may include 3-chloropropyl, Z-ethoxyethyl. carboethoxymethyl. 4-methyl cyclohexyl. pchlorophenyl. p-chlorobenzyl. 3-chloro-5- methylphenyl. etc. The preferred R groups may be lower alkyl. i.e. C C alkyl. groups including e.g.. methyl. ethyl. n-propyl. i-propyl. butyls. amyls. hexyls. octyls. decyls. etc. R may preferably be a tertiary hydrocarbon. most preferably t-butyl. cumyl (i.e.. 2- phenylisopropyl). etc.

In the charge phosphonate. X may be NR- a disubstituted amine group or OR. an alkoxy (including aryloxy etc.) group.

Illustrative of the X groups when X is OR may be methoxy. ethoxy. phenoxy. n-butoxy. and cyclohexyloxy; illustrative of the X groups. when X is NR may be di-ethylamino. dimethylamino. etc.

It will be apparent to those skilled in the art. that the charge phosphonate may be an ester type. an amide type. or an ester-amide type (the latter sometimes being referred to as an estamidel depending on whether both X groups are OR or -NR or whether one X group is OR and the other NR ln the preferred embodiment, the charge phosphonate will be an ester type; and it may have the formula (Ill a (R) P RH Typical of the charge phosphonates which may be employed in practice ofthis invention, may be those set forth in the following table.

TABLE 1 dimethyl vinylphosphonate di-n-propyl vinylphosphonate dicyclohexyl vinylphosphonate N,N,N',N'-tetraethyl diamidovinylphosphonate N,N.N', N'-tetramethyl diamidobuten-l ylphosphonate diethyl vinylphosphonate di-n-butyl vinylphosphonate methyl-N.N'-dimethyl amidovinylphosphonate ethyl-NN dimethyI amidovinylphosphonate N,N.N',N-tetramethyl diamidovinylphosphonate N,l\",-tetra-n-butyl diamidovinylphosphonate The above charge phosphonates may be readily available or they may be prepared as desired. The preferred charge phosphonates may be those where R'H is vinyl and X is (OR) More specifically the preferred phosphonates may be dillower alkyl) vinylphosphonates, most preferably dimethyl vinylphosphonate, diethyl vinylphosphonate, and di-n-butyl vinylphosphonate.

The hydroperoxide RO-OH which may be used as charge to the process of this invention may be a hydroperoxide wherein R is hydrocarbon. The preferred hydroperoxide may be a tertiary alkyl hydroperoxide, (and preferably a C to C lower alkylhydrogenperoxidel such as t-butyl hydroperoxide or cumylhydroperoxide.

In accordance with a preferred embodiment of this invention. it may be desirable to use the charge per oxide. a mixture of the peroxide se and the alkali metal salt of the peroxide. Typically the charge peroxide composition may be employed in the form ofa mixture containing 3 20 parts, preferably l0 parts, say 7.5 parts of the peroxide se, typically tbutylhydroperoxide. and 05 5 parts, preferably 0.5 3, say i part of an alkali metal salt thereofeg, the sodium salt of t-butylhydroperoxide. Preferably the salt used will be a salt of the same peroxide which is also present in free form.

In carrying out the process of this invention in accordance with certain of its aspects, 3 parts, preferably 5 it? parts, say 7.5 parts of the peroxide ROOH may he added to the reaction medium together with 1 5 parts. preferably 2 4 parts, say 3 parts of the charge phosphonate Preferably the amount of peroxide added to the reaction medium may be I00 percent-l0tl0 percent, preferably 250 percent 750 percent. say 500 percent of the equivalent amount required to react with the phosphonatc according to the following reaction:

- R"-OOR A typical specific reaction which may be carried out by the process of this invention may be the following: (the symbol R is used in the formula R' OOH to designate that although this moiety may be selected from the same group as is R, it is not necessarily the same moiety as is R).

I (R0)2 P R'H Rooa (III) (no) P a' -o-on'" Reaction may be carried out at 20-l00C, preferably 20C-40C, say 25C at pressure of 0-1000 p.s.i.g., preferably 0-20 p.s.i.g., say atmospheric pressure The reaction may be exothermic; and accordingly provision for cooling and agitation may be provided.

If desired, the reaction may be carried out in the presence of inert diluent-solvent such as dioxane, or particularly solvent systems such as the mixtures: water-tetrachloroethylene or water-dioxanc. More preferably, however, the reaction may be carried out either in the absence of diluent-solvent or with the talkylhydroperoxide itself as the diluent.

The reaction is preferably carried out in the presence of catalyst in the preferred embodiment. The preferred catalyst may be a basic catalyst, typified by alkali metal salts of hydroperoxides, alkali metal alkoxides, or alkali metal hydroxides. When the alkali metal salt is a salt of a hydroperoxide, it is preferred that the hydroperoxide be the same hydroperoxide as that participating in the reaction. Typical of such basic catalyst may be the sodium salt of t-butylhydroperoxide. When the base catalyst is an alkali metal alkoxide, it may commonly be an alkali metal alkoxide of a lower alkyl (C Cwl alcohol. Typical ofthe alkoxides which maybe employed as eat alysts may be sodium methoxide, potassium t-butoxide. sodium ethoxide, and lithium ethoxide. A typical alkali metal hydroxide may be sodium hydroxide. The preferred catalyst may be the sodium salt of tbutylhydroperoxide.

During the course of the reaction which may occur over 60-200 minutes, preferably [00-150 minutes, say 120 minutes, the reaction may be controlled by cooling. At the conclusion of the reaction as typically ob served by the absence of continuing exotherm, inert hydrocarbon diluent-solvent (in which the catalyst is insoluble) may be added to the reaction mixture. Typical of the inert hydrocarbon liquids which may be added as diluent-solvent may be pentane, hexane, heptanet octane etc., preferably pentane. The inert diluentsolvent may precipitate the base catalyst present in the reaction medium. The precipitated base catalyst may then be filtered off.

The added diluent-solvent. unreacted hydroperoxide, and unreacted vinyl phosphonate may be distilled off at pressure of 1-20 mm. Hg, preferably 10-18 mm. Hg. say l4 mm. Hg. The product phosphonate, obtained in yields up to percent may be purified by column chrommatography using silica gel as adsorbing phase and chloroform as eluent, or alternatively. may be used as is in crude state. In the preferred embodiment. the reaction may be carried out in substantially anhydrous reaction medium.

The novel products which may be prepared in accorthe desired product polyacrylonitrile may be worked dance with the process of this invention may typically up by filtration of the polyacrylonitrile and washing be found to be high boiling liquids. Illustrative specific with 500 parts of n-pentane. A control reaction without products may be those set forth in the following table. the dimethyl-t-butyl peroxyethane phosphonate gave 5 under the same conditions no polyacrylonitrile.

TABLE These novel compositions may also be useful as dimethyl t-butylperoxyethylphosphonate flameproofing agents, when incorporated in plastics dlelhyl y p y y p p (cg, polyvinylchloride) in amount of 0.0l-5 parts. prefp py l-butylperoxycthylphonphonatc erably 0.00l-l parts, say 0.|5 parts per 100 parts of di-n-butyl t-butylperoxyethylphosphonate 10 plastic. it may be noted when these compositions are diphenyl t-butylperoxyethylphosphonate used as initiating agents to polymerize monomers, the dimethyl cumylperoxyethylphosphonatc final product polymer may have incorporated therein diethyl y p y hy p p chemically bound fragments of the initiator; and these diphenyl cumylperoxyethylphosphonate fragments may impart flame-proofing properties to the N,N,N', N'-tetramethyl diamido-2-(t-butylperoxy)- polymer product.

ethylphosphonate It is also a novel feature of the products of this inven- N,N,N', N'-tetramethyl diamido-2-(cumylperoxy)- tion that they may readily catalyze the reaction of hyethylphosphonate drocarbons to permit production of dimers or oligo- N,N.N', N'-tetraphenyl diamido-2-(cumylperoxy)- mers. Typically, for example, cyclohexane may be dih l h h m merized or oligomerized to form dicyclohexane by dih l N N di h id z b l merization in the presence of dimethyl t-butylperoxyethy|phosphonate phosphonate as catalyst. diqnmhyl vbutywemxyethwphusphonam It will be apparent to those skilled in the art that the dimethyl pinaneperoxyethylphosphonate 2S novel (hydrocarbonperoxy) phosphonate Productsi P pared by the process of this invention may be highly active. Accordingly, it may be desirable to store them under conditions conducive to maintaining the integrity of the product. Preferably, these products may be stored under anhydrous conditions and free of any impurities which may assist or participate in the decomposition. They are stable at room temperature; prefera bly they may be stored in a closed opaque vessel.

The novel products prepared in accordance with the process of this invention may be found to be useful for a wide variety of uses. Typically, for example, they may be found to be useful as polymerization initiators for the quantitative polymerization of polymers by radical polymerization reactions. Typical of such polymers. the polymerization of which may be initiated by these novel products. may be noted polymers of vinyl-type p p from eg ethylene vinyl acetate. vinyl chlo- DESCRIPTION OF PREFERRED EMBODIMENTS ride, styrene, butadiene etc. and more particularly acrylic-type polymers prepared from monomers such as acrylonitrile. methyl methacrylate. methyl acrylate,

Practice of the process of this invention may be observed from the following illustrative examples wherein, as elsewhere in this specification, all parts are etc. g

Polymerization of polymers such as acrylics may be parts by we'ght unless Olherw'se noted effected by the use of these initiators by adding 0.0l-l 40 EXAMPLE I 0 CH n l H O H )2 P CH=CH2 (E O parts, preferably ().0l0.l parts. say 0.05 parts of the in this example which represents practice of a predesired polymerization initiator per I00 parts of monoferred embodiment of this invention, 2.7 parts (0.025 mcr. The desired polymerization initiator may be dimoles) of dimethyl vinylphosphonate and a solution of methyl t-butyl-peroxyethancphosphonate. dicthyl l part (0.009 moles) of the sodium salt of tcumylperoxyethanephosphonatc. diphenyl t-butylbutylhydroperoxide in 7.5 parts (0.069 moles) of tperoxyethanephosphonate, N.N.N'. N-tetramethyl 6U butylhydroperoxide may be added to a reaction mediamid zylpb t l) cthylphosphonnle, Ty i ll dium with stirring. As the exothermic reaction occurs, 0.0l-l parts, preferably 0.0l-0.l parts, say 005 parts the temperature may increase from the initial temperaf di hyl phutylpcroxycthuncphusphunute may b ture of 25C up to a final temperature of C. Thereafadded to parts of cg. acrylonitrile optionally disas reaction Occurs r h r. mper ure may drop sowgd in tohlcnc inc" dihmm, M to 25C. At this point, 100 parts of n-pentane may be Reaction mixture may be maintained at 60C and i added and 3 P p 0f Catalyst :Q l4.7 psig for l8 hours during which time polymerizahutylhydmpcmxldc y be The prcclpmm? f m he cffcctcd At the end f this reaction time be filtered, and the filtrate distilled to remove as distillate l parts of n-pentane. 4.8 parts of tbutylhydroperoxide. and 0.9 parts dimethyl vinylphosphonate. 3 parts (0.013 moles) of desired product dimethyl t-butylperoxyethanephosphonate may be ob mined as slightly yellow oil in yield of 65 percent (based on dimethyl vinylphosphonate). Elemental analysis indicated Hzcalc 8.39 percent. found 8.07 percent. P: calc 13.70 percent. found l3.80 percent.

EXAMPLE ll In this example. 4 parts (0.029 moles) of dimethyl vinylphosphonate and a solution of 0.6 parts (0.005 moles) of potassium t-butylate in 7.3 parts (0.08l moles) of t-butylhydroperoxide may be added with stirring to a reaction mixture. The strong exothermic reaction may increase the temperature from an initial C. to a final 65C. at which latter temperature. the reaction mixture may be maintained during the course of reaction. At the conclusion of the reaction, the reaction mixture may be worked up in a manner comparable to that of Example I. Dimethyl t-butylperoxyethanephosphonate may be obtained in amount of 4 parts (61 percent yield).

EXAMPLE "I Four parts (0.024 moles) of diethyl vinylphosphonate and a solution of 0.6 parts (0.005 moles) of potassium t-butylate in l7.5 parts (0.081 moles) of cumyl hydroperoxide (70 percent) may be added to a reaction mixture. As reaction progresses. the temperature may increase from 25C. up to 55C. After 60 minutes. the reaction may be completed and the temperature of the reaction mixture may drop again to 25C. At this time. 200 parts of n-pentane may be added to the reaction mixture to precipitate catalyst potassium tbutylate. The precipitated catalyst may be filtered off. The filtrate may then be distilled to recover as distillate. solvent and excess diethyl vinylphosphonate. The desired crude product, diethyl betacumylperoxyethanephosphonate may be further purified by preparative thin layer chromotography. A silica gel adsorbent is used with chloroform and l percent ethanol as mobile phase. The desired product obtained in the amount of 1 part (8 percent yield) may be isolated and upon analysis may be found to contain 8.l l percent hydrogen (calculated 7.99 percent) and 9.0 percent phosphorus (calculated 9.8l percent).

EXAMPLE IV In this example which represents practice of a process carried out in accordance with this invention. 2.4 parts (004 moles) of acrylonitrile may be admitted to a sealed tube in the presence of 0.006 parts (0.00002 moles) of dimethyl t-butylperoxyethanephosphonate.

0.538 parts (0.0024 moles) of dimethyl tbutylperoxyethanephosphonate and 8.9 parts (0.06 moles) of cyclohexane may be placed in a tube, and degassed with nitrogen. The tube may then be sealed and heated to l20C. for 24 hours. At the end of this time, the reaction mixture may be extracted with cyclohexane and analysis of the cyclohexane-soluble fraction by gas chromotography may show the presence of bicyclohexane.

EXAMPLE Vll CH CH It will be apparent to those skilled in the art that this invention has been described with respect to specific embodiments; and numerous changes and modification will be apparent which fall within the scope of this invention.

We claim:

n X 2 P R 00R wherein R is a hydrocarbon containing less than about 3. 18 carbon atoms and R may be inertly substituted. R" is divalent hydrocarbon containing 2-10 carbon atoms 9 and R may be inertly substituted and X is OR or NR.,. (RO) P CH CH 00R wherein R is lower alkyl. 0 4 n (R0) P R" 00R 10 o 2 u (ca o) P 0H c11 OO-t-Bu wherein R is lower alkyl and R" is divalent hydrocar- 3 bon wherein R and R" may be inertly substituted. 

